1. Field of the Invention
This invention is directed to the field of multi-colored dyeing of polyamides and in particular polyamide carpets.
2. Background of the Invention
Numerous mechanical means are available for the printing of multi-colored patterns on textiles. Additionally, various displacement and resist techniques have been attempted to produce multi-colored dyeings of polyamides such as wool and nylon; particularly multi-colored dyeings of polyamide carpeting.
The best known and most widely used resist/displacement system for producing multi-colored patterns on polyamide carpeting was developed by the Sandoz Company of Basel, Switzerland. This Sandoz system was developed in the late 1970 to early 1980 period and was known as "Lanasyn.RTM.S/Thiotan.RTM.TR System". In practicing this system by the resist method, a standard acid dye and cationic chemical (a tallow diamine--ethylene oxide--quat) known as Thiotan.RTM.TR were placed on the substrate in a desired pattern. Then at the last application point in the textile dyeing line, monosulfonated, 2:1 premetallized acid-type dyes called "Lanasyn.RTM.S dyes" were flooded on to the substrate. The cationic chemical complexed with the monosulfonated, 2:1 premetallized acid dye and prevented its fixation in the printed area. The substrate was then steamed to fix the dyes and produce a multi-colored pattern. In the displacement method, the Lanasyn.RTM.S type dye was applied to the entire surface of the substrate. Next one or more displacement prints were made over the substrate with a mixture of a monosulfonated acid dye and the cationic chemical. Again the cationic chemical complexed with the Lanasyn.RTM.S type dye which prevented its fixation. Steaming fixed the uncomplexed dyes producing an acceptable multi-colored pattern.
This prior art system, although commercially acceptable, had several drawbacks. It was not possible to prevent complete fixation of the Lanasyn.RTM. type dye in the area treated with the cationic chemical. Secondly, although the cationic chemical did selectively complex with the premetallized dye, it also complexed with the standard acid dye. In pale shades up to half the standard acid dyes could be lost. Third, the cationic compound of this system also complexes with anionic stainblockers used in the after-treatment of polyamide carpets to render them stain resistant to acid dyes found in foods and drinks. The complexing of the anionic stainblocker with the cationic chemical renders the stainblocker ineffective. The present invention overcomes all of these disadvantages.